Dinosaurs.

Evolution does not work that way. If a group is a true group, ie monophyletic, they all descend from a single common ancestor. That chances of another species evolving not just in parallel (which is common) but into genetically the same taxa is so small that we'd expect all the statues in the world to wave due to atomic vibrations lining up in just the right way before it ever happened. The "raptors" we all know (Deinonychosauria) are not their ancestors either, they are all Cretaceous species and birds evolved in the Jurassic. Though they are indeed the most bird-like of known non-avian species, meaning either they continued evolving along many of the same lines, have a similarly bird-like Jurassic ancestor that we (or I) do not yet know of, or else those particular dinosaurs are in fact the earliest flightless birds.

The pterosaurs are completely different from birds, and indeed from anything else. I don't doubt that if they had survived the KT extinction they would have produced an entirely new and unique class of vertebrates. Probably flightless, given the way birds were taking over the skies and the way the last of the pterosaurs spent a good deal of time on the ground anyway. Example of their uniqueness: their "hairs" that made up the fur on their bodies was not hair at all, but a unique fibre called "pycnofibres".

http://scienceblogs.com/tetrapodzool...azhdarchid.jpg

You are right on both counts. As we increasingly classify organisms by their evolutionary relationships rather than appearance, the old Linnaean taxonomy is falling out favour for the new cladistics. Now, reptiles as a class is not complete without the mammals, birds and synapsids (a group now extinct except for the mammals, without which it is incomplete). I would say the same for fish, except "fish" does not correspond to an scientific group, being made of multiple classes more different from each other than we are from (some of) them.

Including every clade and taxon I can find and figure, birds (Aves) fits into the tree of life like this:

-- actually, this is going to be harder than I thought.

Superregnum: Eukaryota (nucleated cells)
Supergroup: Unikonta (single or no emergent flagellum)
Cladus: Opisthokonta (posterior flagellum)
Cladus: Holozoa (Fungi excluded here)
Cladus: Filozoa (Animals and nearest unicellular relatives closer to animals than Fungi)
Regnum: Animalia/Metazoa (Animals)
Subregnum: Eumetazoa (Sponges excluded here)
Cladus: Bilateria (Bilateral symmetry, Cnidarians excluded here)
Cladus: Nephrozoa (God knows)
Cladus: Deuterostomia (the blastopore becomes anus. Protostomia excluded here)
Phyla: Chordata (animals with a notochord)
Cladus: Craniata (has skull, "fish" start here)
Subphyla: Vertebrata (fish with spinal column, lampreys & hagfish excluded here))
Infraphylum: Gnathostomata (jawed fish)
Microphylum: Eugnathostomata (really jawed fish)
Classis: Chondrichthyes (cartilaginous fish. Sharks etc)
Cladus: Teleostomi (Osteichthyes and Acanthodii ("spiny sharks"). Sharks excluded here)
Superclassis: Osteichthyes (bony fish, Acanthodians excluded here)
Classis: Sarcopterygii (lobe-finned fish. Ray-fins (classic fish) excluded here)
Cladus: Rhipstidia (coelacanths excluded here)
Subclassis: Tetrapodomorpha (Lungfish excluded here)
Superordo: Osteolepiformes (Rhizodonts excluded here)
Ordo: Elpistostegalia (the fishapods)
Familia: Panderichthyidae (also fishapods)
Superclassis: Tetrapods (four legged vertebrates. All fish excluded here!)
Classis: Amphibia
Subclassis: Labyrinthodonta (ancestral to all land-living vertebrates)
Ordo: Reptiliomorpha (reptile-like amphibians)
Cladus: Amniota (terrestrially adapted eggs, essentially the reptiles)
Cladus: Sauropsida (synapsids (including mammals) excluded here)
Classis: Reptilia (all other birds and reptiles)
Cladus: Eureptilia (Anapsids excluded here (meaning turtles)
Cladus: Romeriida (Diapsids and Protorothyrididae)
Subclassis: Diapsida (Reptiles with two holes (temporal fenestra) in each side of their skulls)
Infraclassis: Archosauramorpha (ruling lizard forms)
Divisio: Archosauria (ruling lizards)
Subsectio: Avemetatarsalia/Panaves (crocodiles excluded here)
Subsectio: Ornithodira (Scleromochlids excluded here)
Subtaxon: Dinosauromorpha (pterosaurs excluded here)
Series: Dinosauriformes (dinosaurs + basal forms)
Superordo: Dinosauria
Ordo: Saurischia (lizard-hips, ornithischians excluded here)
Taxon: Eusaurischia (Herrerasaurids excluded here)
Subordo: Theropoda (Bipedal, mostly predators. Sauropods excluded here)
Subsectio: Neotheropoda (basal theropods excluded here)
Infraordo: Tetanurae (Ceratosauria excluded here)
Taxon: Avetheropoda (Megalosaurids & Spinosaurids excluded here)
Taxon: Coelurosauria (Carnosauria excluded here)
Taxon: Maniraptoriformes (Compsognathids excluded here)
Taxon: Maniraptora (Ornithomimosauria & Tyrannosauroidae excluded here)
Apomorphy: Aviremigia (all dinosaurs with pennaceous feathers)
Taxon: Paraves (Oviraptorsauria excluded here)
Taxon: Avialae (Deinonychosauria excluded here)
Classis: Aves (Birds. Scansoriopterygids & perhaps Archaeopteryx excluded here)

Whew! You know, if I, or anyone, had the required data we could break every line here with another whole sequence (and break those lines too) such that we get down to the exact species in the whole lineage. As it is, I was a bit iffy about getting as specific as Panderichthyidae.

But as you can see, there's no way to count all reptiles and not birds without arbitrarily excluding them. They sit on the same branch of the tree of life, which is rented from the fish. Also, sea scorpions (Eurypterida) were arthropods, which are protostomes. They branched off my list at line nine. Humans branch off at twenty-nine.



Moxco has the abridged version.

I thought that there was some discrimination between the species of raptors as to which had feathers and which didn't. For some reason I'm thinking that the Utah Raptor was heavily feathered [and by 'heavily' I just mean for a fucking dinosaur] and others were 'naked', if you'll pardon the term.

Species basal to these groups are known to have feathers, so unless they were secondarily lost, they would have had quite the plumage. As you can see above, the Deinonychosauria (Dromaeosaurids and Troodontids) fit within the Aviremigia, all of which had penneceous feathers. These are advanced feathers with a central shaft, vanes and flattened barbs, with barbules connecting the barbs. Essentially, modern feathers (flight feathers are an asymmetrical modification of this design).

It is reasonable to assume that other theropods outside of Aviremigia had feathers also, but of more primitive structure. Looser with no barbules, for example, or radial and downy.

Many recent finds of well-preserved dromaeosaurids (raptors) from places like the Liaoning province in China are basically whole skeletons in rock slabs, and in many of them, including Microraptor, Mei Long, Sinosauropteryx and many small, carnivorous relatives like Caudipteryx, there is a ring of feather imprints surrounding the skeletons like a halo.

Now we only found the primary feather indents in the arm of Velociraptor after examining the bone carefully. If I had to guess, the only reason we haven't found similar structures, or these "feather halos" around the bones of species we'd known about for a long time, like Deinonychus or Utahraptor, is because we simply weren't using the same delicate techniques we use now. Another reason is that we just weren't looking for them. Feathers on dinosaurs is a fairly recent revelation in the field of paleontology, so perhaps with further examination and a more surgical excavation, we'd get a more definitive answer.

I need to mention that I don't think we've excavated enough of Utahraptor to even know if it was feathered or not; just a claw and perhaps a bone or two. I think you may have meant a different species, because I've never seen confirmation of that.

What I'm saying is this: paleontology is guess work. A lot of really educated guess work, and it's a safe bet to assume that since we've discovered so many dromaeosaurids with feathers, that most "raptor" dinosaurs were probably feathered, to a certain degree, factoring in variables like climate and evolutionary development and use of the feathers. Most animals on that branch of the evolutionary tree were also feathered (since not all feathers must be used for flight).

Since these primitive feathers were more like fur than contouring, complex feathers of modern birds, it's smart to imagine that, like mammals, the bigger the dinosaur got, the less feathers it may have had. Elephants have almost no fur, while felines have fur at different lengths, depending on their environment.

It's a really recent development in paleontology, so I expect we'll find out a lot more in the years to come.

Hopefully.

Thanks for this.



In more pet related news, it looks like I'll be adopting/rescuing a Pit Bull puppy in a couple of weeks. I really want to name it Morgan Freeman.

I know you can't talk shit about Pit bulls on the internet without everyone getting up at you and blaming all the attacks on irresponsible dog owners and I do recognise that a vast majority of unprovoked Pit bull attacks are from lazy/ignorant/stupid people who didn't train and socialise them properly as a puppy. But seriously, what do people see in Pit bulls, I'm sure they can be friendly dogs but so can any other breed of dog.

So yeah, why a Pit bull? I'm not criticising you, I'm just curious.

Because the breed has amazing traits. They're incredibly empathetic and in tune with people in general, but to a freakish extent with those they've bonded with. They tend to be highly intelligent, determined, and are perpetually eager to please.

They're also one of the most gentle breeds you can find for their size. My last dog was a Pit that I rescued from 'death row' at the shelter, and was a true ambassador for the breed. She made friends with dogs, children, and adults wherever she went. She was especially fond of children under four years of age, and took a protective attitude with them, even strangers.

These dogs have an amazing and almost heroic history, but because of their involvement in illegal dog fighting, people tend to view them as the monsters they're not. Out of the 50 infamous Pit Bulls that were confiscated from Michael Vick's property, only one had to be put down because there was no hope for rehabilitation, and that was more a case of over-breeding and mental deterioration than outright viciousness. The rest have been successfully rehabbed, and while several have had to be moved permanently to sanctuaries for abused animals, the remainder have been fostered and adopted. Several of those have become certified therapy dogs. I think that, more than anything, speaks volumes about the true nature and spirit of the breed.



So to answer your original question of " why a pit bull?"

Because it will always be a Pit bull. Always. These are the dogs that get put to sleep because of their breed, not their disposition. I don't just feel sorry for them. I see big-headed silly dogs that have been over-bred, mistreated and misrepresented for decades. If I can save a Bully or two, great.